"Shankarlal Guru and Joseph Massey appeared before us today and we grilled them for several hours, seeking answers related to the payment crisis," said an official of Economic Offences Wing (EOW), without disclosing detail.

Massey was also one of the directors of NSEL.

Sinha, who in an affidavit filed before a Mumbai Court had blamed the entire former senior management, including himself, for the payment crisis, will be appearing before the investigators tomorrow, he said.

"His interrogation will throw light on some unanswered questions. His revelations would be crucial and we are ready to ask him some tough and straight questions."

EOW had summoned Sinha after registering an FIR on September 30, but he did not appear before the Mumbai Police agency citing ill health. "Sinha has now communicated to us that he would present himself tomorrow," the officer added.

Sinha, in the affidavit, claimed he suspected that some of the former senior management executives had entered into dealings with buying members of NSEL for their personal benefits and demanded a judicial inquiry against them.

He admitted submitting "wrong stock statement" to the NSEL Board and commodity regulator FMC based on the report by the warehousing division of the exchange.

Taking the blame for not informing the Board about increasing exposure and risk of widespread defaults, Sinha stated the management allowed the exchange to function and did not stop trading due to fear of defaults.

Citing several instances of misrepresentation of stock position and fund diversion, Sinha said buyers diverted funds availed through fictitious sale transactions to purchase real estate and other properties.

Two former executives of NSEL were arrested last week in connection with the scam. Sinha found fault with the business development team for introducing buyers with bad credentials into the NSEL system.

He blamed the warehousing team for not having adequate control on physical stock and for making "false stock statement".